Less humidity, cloud cover, etc.

Not only can you see the orange color of Mars with the naked eye you almost feel you can see the canals on the clearest nights or when you get further out of the light pollution of the cities.

It's no wonder all the Mars probes are controlled from right here and ASU gets so much of the space business.

Where else can you go out in your yard poolside and watch Mars at midnight when its 95 degrees outside?

;-)

And if 116 degree days are too hot for you...well than you're just being wimpy.

SDAI-Tech1

PS. And if you go out to Lowell Observatory they sell really cool, long, purple, gold-fleck pencils in the gift shop.